Some conventional wireless networks utilize a sleep mode to reduce the power consumption of mobile stations and decrease usage of serving base station's air interface resources. In WiMAX networks for example, for each involved mobile station, the serving base station may maintain one or more contexts related to predefined power savings classes (PSCs). A PSC is a group of connections that have common demand properties. PSCs may differ by their parameter sets, procedures of activation/deactivation, and policies of mobile station availability for data transmission.
In current WiMAX networks, to change a PSC (e.g. a PSC of Type II) a mobile station first sends a Mob-SLP-REQ message to de-activate the currently active PSC and then sends another Mob-SLP-REQ message to active another PSC. This message exchange is costly both in terms of the signaling overhead as well as the latency to implement the change. As a result, sleep mode operation in accordance with the current IEEE 802.16 standards fails to take full advantage of changes in traffic activity in an efficient manner.
Thus, what is needed is a mobile station and method for sleep mode operation with reduced signaling overhead and reduced latency. What is also needed is need is a mobile station and method for sleep mode operation that is more responsive to changes in traffic activity resulting in reduced power consumption.